1. Field
The described technology relates generally to a battery module. More particularly, the described technology relates generally to a rechargeable battery with an improved case structure inserted with an electrode assembly.
2. Description of the Related Art
Unlike primary batteries that cannot be recharged, a rechargeable battery (i.e., a secondary battery or a secondary cell) can be repeatedly charged and discharged. A low-capacity rechargeable battery is commonly used for small portable electronic devices such as mobile phones, notebook computers, camcorders, and the like, and a large-capacity battery is commonly used as a power source for driving motors of a hybrid electric vehicle and the like.
A high-power rechargeable battery using non-aqueous electrolyte with high energy density has been recently developed. For example, the high-power rechargeable battery is constructed with a high-capacity rechargeable battery having a plurality of rechargeable cells coupled to each other in series such that it can be used as a power supply for driving motors in electric vehicles requiring high power.
As stated, high-capacity rechargeable batteries are commonly formed with a plurality of rechargeable cells coupled to each other in series. The rechargeable battery may have a cylindrical shape or a prismatic shape.
The conventional rechargeable battery typically includes an electrode assembly with positive and negative electrodes and a separator interposed between the two electrodes, a case mounting the electrode assembly therein, a cap plate fitted and sealed to the case and having terminal holes, and terminals inserted into the terminal holes of the cap plate and protruded to the outside of the case.
Among the conventional rechargeable batteries, a lithium ion battery is particularly used as a small mobile battery. It is also mainly uses a small metal can or a film pouch as exterior materials, and induces a solid sealing structure through welding or melting for isolation between the inside and outside of the battery. However, when the rechargeable battery is developed as a medium-sized battery for electric vehicles such as an HEV, a PHEV, an EV, or a power storage unit, the conventional small battery is not appropriate to be a part of the medium-sized battery system because of high current and high voltage, such that improvements thereof are required.
Upon developing the large capacity battery system, it is preferable that the battery is managed as a system of the battery module with a capacity of more than several tens of Ah (Ampere-hours) or several hundreds of Ah, outside the concept of the single cell. When the conventional small battery is included in the large capacity battery system, the number of cells is increased such that it is difficult to compose and manage the system, and cost is increased.
Accordingly, it is easy to compose the battery module for realizing the medium-sized battery system, and a battery exterior with reliability is necessary.
The above information is only for enhancement of understanding of the background of the described technology and therefore may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.